6/22/22 Wednesday 6:15 am
Not a lot has changed in the big picture. It still looks like we will get somewhere between decent rains and downpours between now and the end of the month, depending on which model is your favorite. Technically, the transport mechanism for the monsoonal flow is not traditional. Nerdy types could argue that this isn’t “it”, it is not THE monsoon. I refuse to split hairs on this. I don’t care what “it” is, I like “it”.
I had planned to do a mid-morning update after the high-resolution models were generated, but I decided not to. NWS has no radar until at least July 1st because of maintenance issues. So the mesoscale stuff is literally out the window right now. They are doing their best with high-resolution satellite as an alternative. In hindsight, this scheduled maintenance would have been done at a perfect time if June was more “June-like”. Anyway, if you are noticing radar outages on your apps, that is why.
There is an impressive amount of moisture building into the forecast area and it will remain for a couple of days during the first wave. During the monsoon season, I talk about Precipitable Water values a lot. Also known as PWAT, this is a measure of the total amount of precipitation that would fall from a virtual column of moisture if it all fell at once. It is often measured in a percentage of the climatological average. This morning’s readings are already pushing 200% of average in some of the forecast areas.
Regional view showing what is here now, and on the way.


(percentage of average)
I put the maps in motion to track this moisture between now and Friday at 6 pm.

Before I post the overnight model runs I want to insert my standard caveats. I am not a big fan of trying to time every drop or flake of precipitation. I don’t usually like to break up the precipitation events because I think there is a certain amount that will fall in total. Timing out each wave and lull is tricky and usually inaccurate.
That being said, I am going to go against everything I normally say and post the forecast totals for the first wave of precipitation. At the moment anyway, it looks like we will have the first wave start today and end Friday or Saturday. There will be a few lulls. Over the weekend I expect pop-up showers Saturday afternoon with the second wave of more steady rain coming Sunday through Tuesday night or Wednesday morning.
Here are the forecast totals for the first wave.
GFS


Canadian


German


NOAA’s NDFD


NOAA’s WPC


Last but not least, the Euro came in with a very impressive run across the southern portions of the forecast area.


I will update again later this afternoon. Thanks for following and supporting the site!